Valid name, no data record of the requested type.
The name is known to the name server, but has no IP
address associated with it--this isn't a temporary
error. Another type of request to the name server using this
domain name will result in an answer (e.g. a
mail-forwarder may be registered for this domain).

NO_RECOVERY

Unknown server error. An unexpected server failure was encountered.
This is a nonrecoverable network error.

TRY_AGAIN

Nonauthoritative answer: Host name lookup failure.
This is usually a temporary error and means that the
local server didn't receive a response from an authoritative
server. A retry at some later time may succeed.